What is the problem with dump stations? It takes only a few minutes to empty the black and grey tanks...

If you have a black and grey tank....

I don't have one or the room for one. The cassette makes sense and it is no more difficult to deal with than a portable toilet. However it does comply with the rules where certain authorities insist on having a fixed in place toilet.

The up side to the cassette or a portta potti is you don't need a dump station. You can dump in any toilet, even an outhouse. The down side is that the tanks are smaller requiring more frequent dumping.

This is a very time-worn and often repeated debate with no definitive answer. Everybody has their opinion, and there are as many opinions as to which they prefer as there are people responding. It's really all about what YOU feel will work best for YOU. All I can say is there are pros and cons to both. I've had both, and I prefer to have holding tanks that I can dump at the dump station or hook up to at the campsite if provided. The older I get, the less that the prospect of lugging some heavy tank around the campground to find a place to dump it appeals to me. If I don't have a site with hook-ups, I prefer to just drive up and pull a lever rather than schlog around a heavy tank full of crap.
Additionally, I find that pulling out a Porta-Potty and sitting in the trailer aisle way doing my business just doesn't appeal to me. Call it a "bad visual" if you will. If space limitations don't permit installing real holding tanks then I guess that you really don't have an option. If you do have an option I would say go with regular holding tanks. Just my 2 cents, but I think that you wouldn't regret it in the long run. I find it so much more convenient, less physical work, and much cleaner to dump than splashing it all over in a toilet or outhouse that other people have to use as well. (That is another area which really doesn't have room here without hijacking the thread,) but there's nothing worse than walking into a campground bathroom where some inconsiderate Porta-Potty dumper spills half of it all all over the toilet and the floor. And trust me, there are a lot of rude inconsiderate campers who do exactly that.

As to dumping built-in holding tanks, it can usually be done in a quite sanitary way, and with just a few minor modifications it can be virtually a "white glove" job. I installed an aftermarket flusher in my black and gray tanks which have a jet sprayer that completely cleans out the tanks, (one for each black and gray tanks,) where you just attach a short section of garden hose to each inlet and it does all the work. No silly garden hose and flusher wand to drag into the trailer to blast your tanks when dumping.
Here's a few pics of my black tank flusher installation. The gray tank hook-up is similar but doesn't even enter the trailer. It's all plumbed to the gray tank completely underneath. Incidentally, because I know the comment will arise, the tank sprayers have built-in one way check valves which prevent back-flow, and I don't use my potable water hose for flushing purposes anyway.

Here is another option. My Parkliner is currently being built with a composting toilet. I like the idea of the cassette on the Lil' Snoozy but chose the Parkliner. It comes down to personal preference.

Here is another option. My Parkliner is currently being built with a composting toilet. I like the idea of the cassette on the Lil' Snoozy but chose the Parkliner. It comes down to personal preference.

...I installed an aftermarket flusher in my black and gray tanks which have a jet sprayer that completely cleans out the tanks, (one for each black and gray tanks,) where you just attach a short section of garden hose to each inlet and it does all the work. No silly garden hose and flusher wand to drag into the trailer to blast your tanks when dumping.
Here's a few pics of my black tank flusher installation. The gray tank hook-up is similar but doesn't even enter the trailer. It's all plumbed to the gray tank completely underneath...

Thanks to everyone for their input. As a future newbie, I appreciate the education. My two main concerns are being able to carry the cassette (I use to work with horses and a 10 gal water bucket is very heavy), and easy disposal of the tank or cassette. I'm 62 years old, and carrying a heavy cassette, and lifting it to dump it, is something that I don't want to deal with.

Casita Greg: Did you install the holding-tank flushes yourself? I'm reluctant to get into mucking about with the plumbing on our new-to-us Casita. But I'd sure like a flush valve, especially on the black-water tank. When we were shopping a couple of months ago, I noticed that many of the new stickies have them built in.

Casita Greg: Did you install the holding-tank flushes yourself? I'm reluctant to get into mucking about with the plumbing on our new-to-us Casita. But I'd sure like a flush valve, especially on the black-water tank. When we were shopping a couple of months ago, I noticed that many of the new stickies have them built in.

/Mr Lynn

Yes I did install it myself. The particulars about the install that I had posted on the Casita forum are here below:

I used a standard 4" hole saw to cut through the dinette bench cabinet and on through to the fiberglass bathroom partition wall. This "sandwich" is about an inch in thickness measuring from the fiberglass wall of the dinette bench, the carpeting in between, and the rear wall of the bathroom. Once through the bathroom wall (drilling forward from the underside of the dinette bench) you will find an air gap of about 3/4" before you run into the side of the black water tank itself. Your pilot bit will probably punch into the side of the black water tank by the time you finish cutting the 4" hole through the bathroom partition, but this is not a bad thing, as it will serve as your reference centerpoint for the smaller hole you'll need to install the quickie flush sprayer (J C Whitney, cat. # 810951, about $25 bucks). The trick here is to develop a "touch" for when you have cut through the partition, and go slow so as not to cut a 4" hole in the side of your black water tank!

The rest is pretty straight forward plumbing using a few feet of reinforced plastic tubing (got mine at Lowes) and some barbed connectors (2 with threaded and barbed fittings and 1 double barbed elbow), and and 4 stainless steel screw clamps to attach it to the threaded fittings to the sprayer and the inlet (standard trailer water hose inlet fitting available at any RV supply) which needs to be mounted in the sidewall of the trailer where it will come in under the front side dinette bench. To seal the sprayer to the side of the black water tank I used a good marine grade permanent sealer (such as 5200 or equivalent.) I would caution against using anything like common bathtub caulking as it isn't strong enough and you certainly don't want this one to leak.

In case anyone was wondering, the sprayer unit does have a built-in back-flow preventer to keep "black water" from flowing in reverse, but I still use a dedicated hose for flushing and another for potable water, just to be safe. I also incorporated quick detach hose fittings to the trailer inlet and the flushing garden hose just for added convenience.

This mod is one of my favorites, and every time I flush my tank I am so happy I did it. No more pulling a hose and wand through the window anymore.

The up side to the cassette or a portta potti is you don't need a dump station. You can dump in any toilet, even an outhouse. The down side is that the tanks are smaller requiring more frequent dumping.

Signs in the outhouses of a BC Forest Service campground that I frequent say you are NOT to dump porta pottis.
I suspect that the people who get to clean the washrooms in campgrounds with flush toilets are not happy to follow someone who dumped in their facility either.

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